Kaizen practices and performance improvement in Zambian manufacturing companies

Abstract

There is strong evidence that Zambian manufacturing organisations are increasingly implementing Kaizen programs to help them improve productivity and enhance delivery performance. This study aims to investigate the relationship between Kaizen practices and improvement in performance in Zambian manufacturing companies. The study also sought to determine the challenges faced by manufacturing companies in implementing Kaizen practices. The study employed a cross-sectional descriptive research design with the target population being manufacturing companies in two highly industrialised regions in Zambia. Thirty-three questionnaires were distributed, and 31 companies responded. Based on the conceptual framework developed, hypotheses were formulated and tested using the ordinary least squares regression modelling approach. The results show that the 5Ss were the most popular activities implemented, while the Suggestion System was the least implemented. Implementing Kaizen practices leads to significant operations performance improvements in manufacturing companies in the form of productivity, quality, and overall equipment effectiveness. The results also show that employee attitude is the major challenge in implementing Kaizen, while management support or leadership is the last hurdle. The research provides an early understanding of the successes of the implementation of Kaizen practices in manufacturing companies in Zambia.

Keywords:

• employee attitudes
• Kaizen practices
• manufacturing companies
• performance improvement
• Zambia

PUBLIC INTEREST STATEMENT

To build an industrial nation that sees a strong and dynamic middle-income industrial nation that provides opportunities for improving well-being, there is a great need for increased productivity and quality in the products and services produced. Zambian manufacturing firms have adopted Kaizen principles to contribute to the country’s goal of being a successful middle-income nation by improving operational performance. This study investigated the relationship between Kaizen implementation and operational performance improvement in Zambian manufacturing organisations. Firstly, the value of this research was to inform management, the Kaizen Institute of Zambia, and government policymakers about the successes of the implementation of Kaizen practices in manufacturing companies in Zambia. Secondly, the value of this research was to highlight the challenges faced by manufacturing companies in Zambia in implementing Kaizen practices so that more resources could be directed at reducing these challenges so that companies can enjoy the benefits of Kaizen practices.

1. Introduction

Following the economic liberalisation in the 1990s, the Zambian industrial sector underwent significant economic reforms to structurally adjust the economy to ensure dynamism, efficiency, and competitiveness by the private sector (Government of the Republic of Zambia (GRZ), 2014). There was a policy shift away from import substitution, protectionism, and heavy public-sector involvement toward the promotion of a private sector-led market-oriented economy. Consequently, most state enterprises were privatised.

Since the mid-1990s, the performance of the manufacturing sector has been positive, albeit with fluctuations (Zambia Development Agency (ZDA, 2014). The manufacturing activities in the country are undertaken by the private sector players, with the government providing a conducive business environment through policy guidance. Further, the government has put in place interventions to support the manufacturing sector, such as establishing Multi-Facility Economic Zones (MFEZs) and Industrial Parks and providing sector-specific investment incentives (ZDA, 2014). The government also promotes small and medium enterprises (SMEs) in labour-intensive light manufacturing activities to promote the growth of the industry.

The manufacturing sector in Zambia now accounts for about 11 percent of the country’s Gross Domestic Product (GDP) and has been growing at an average annual growth rate of three (3) percent in the last five years. Growth in the sector is mainly powered by the agro-processing (food and beverages), textiles, and leather subsectors. Secondary processing of metals is one other major activity in the sector, particularly the smelting and refining of copper, and this has contributed to the manufacturing of metal products. Construction materials such as cement as well, fertilisers, chemicals, and explosives are also produced in the sector. Other activities include wood products and paper products.

1.1. Kaizen concept in Zambia

Several techniques for improving productivity and indeed performance in manufacturing organisations have been developed over the years, such as lean manufacturing, Kaizen, Business Process Re-engineering, Statistical Quality control, Total Quality Management, and many others (Fiorillo et al., 2021; Nderi, 2012). The Kaizen concept developed in the 1950s is one of the all-encompassing concepts of many Japanese business practices. Kaizen is a compound word involving two Japanese concepts: Kai (change) and Zen (for the better) (Liker, 2004, Palmer, 2001). The concept indicates a process of continuous improvement of the standard way of work (Singh & Singh, 2012). Kaizen has become very popular in many parts of the world, although Nderi (2012) argues that much as Kaizen transformed many Japanese companies into world-class companies, its success outside Japan is highly contestable.

According to the Ministry of Commerce, Trade and Industry, hereafter (MCTI), the need for continuous improvement in the Zambian manufacturing industries cannot be overemphasised in the wake of increasing competition which has rapidly become a major problem for Zambian manufacturing industries.

Owing to the significant contribution of the manufacturing sector to the Zambian economy, it is imperative to study the effectiveness of the improvement techniques such as Kaizen being implemented in the sector. The Kaizen concept is a relatively new concept in Africa and Southern Africa in particular. In Zambia, only thirty-three (33) companies had adopted the philosophy by the end of 2015, and most of these had less than 4 years of experience with the concept (Kaizen Institute of Zambia (KIZ) News Letter No. 3, 2015). These companies adopted Kaizen by participating in workshops and lessons offered by experts in Kaizen. Studies of the relationships between Kaizen implementation and organisational performance in some countries outside Japan have shown a relatively strong link in countries such as Ethiopia and Kenya (Berhe, 2021; Desta et al., 2014; Nderi, 2012).

However, no similar research has yet been conducted in Zambia. Therefore, being a relatively new concept in the Zambian context, research to ascertain the extent to which Kaizen activities have been understood and improved the operations’ performance is needed. This research will, therefore, study the relationship between Kaizen implementation and improvement in operations performance in Zambian manufacturing companies. The specific objectives of the study are as follows:

• To ascertain the extent to which Zambian Manufacturing companies implement Kaizen practices.

• To establish the challenges being faced by the Zambian Manufacturing companies in implementing Kaizen.

• To determine the relationship between Kaizen implementation and improvement in operations’ performance in Zambian manufacturing companies.

This paper is arranged as follows: the next section reviews the literature on Kaizen as a performance improvement tool. This is followed by developing a conceptual framework and methods in sections 3 and 4, respectively. Section 5 used presents research findings, discussion, and conclusion.

1.2. Literature review, conceptual framework, and hypotheses

1.2.1. The Kaizen concept

The Kaizen philosophy originated in Japan, where it was dedicated to the improvement of productivity, efficiency, quality and business excellence. Kaizen is an internationally acknowledged method for continuous improvement involving minor improvements in key organisational processes (Murmura et al., 2021). Unlike many Japanese philosophies, Kaizen forms an umbrella concept that covers different techniques, including Kanban, total productive maintenance, six sigma, automation, just-in-time, suggestion system and productivity improvement, and many others (Fiorillo et al., 2021; Singh & Singh, 2012). The Kaizen philosophy sits on three pillars for successful implementation; these are housekeeping, waste elimination, and standardisation (Murmura et al., 2021).

In manufacturing, Kaizen is associated with locating and eliminating waste in machinery, labour, or production procedures. McDermott et al. (2022) further added that Kaizen is a process of focused and sustained innovation throughout the organisation that is in the form of small logical, incremental projects known as Kaizen events. Gupta et al. also affirm that Kaizen strategies bring great gradual improvements in organisations in the form of growing the effectiveness and efficiency of the processes, enhancing the visibility of the process, improving the confidence and safety of workers, and reducing waste and unsafe conditions. Kaizen has a large horizontal improvement and can be applied in all organisation workstations (Murmura et al., 2021; Desta et al., 2014).

Although many firms have achieved process improvement through the implementation of continuous improvement programmes, the initial improvement is easily eroded back to the pre-improvement level, especially if the three pillars are not adhered to (Mano et al., 2014; McDermott et al., 2022). It is important to note that Kaizen is not only restricted to manufacturing, but the philosophy is also a way of life that can be applied to service and not-for-profit organisations, for example, hospitals (Fiorillo et al., 2021).

This research invokes the knowledge-based view to help provide an explanation of the relationship between Kaizen activities and operational performance. First, a firm participating in programs such as Kaizen can acquire knowledge that can help them create capabilities that can be used to continuously improve productivity, quality of products produced, speed and flexibility of operations, and overall equipment effectiveness. A firm can acquire team-based capabilities by participating in a series of knowledge acquisition programs such as Kaizen (i.e., constant improvement techniques; McDermott et al., 2022). In this regard, “participation” is defined as attending workshops and lessons conducted by experts. The participation of people in such activities is also usually considered a means of developing key skills in the employees. In Japanese companies, Kaizen is applied to make employees feel comfortable in the company. Kaizen activities help to increase communication among employees and therefore improve the well-being and motivation of the people working there (Carnerud et al., 2018). The knowledge-based view (Marzec, 2013) draws attention to how knowledge is created in organisations through the knowledge management process of socialisation (tacit to tacit), externalisation (tacit to explicit), and combination (explicit to explicit), as well as internalisation (explicit to tacit). The knowledge-based perspective equally supports a knowledge development performance relationship. Building upon the resource-based perspective’s notions of value, inimitability, and rarity, the knowledge-based perspective centres on the notion that distinctive capabilities to create and also exploit wisdom, enhance outcomes and thereby create competitive advantages (Murmura et al., 2021; Alvarado-Ramírez et al., 2018).

1.2.2. Kaizen systems

Kaizen is implemented through systems that must work in a coordinated manner. There are a number of systems and practices that fall under the umbrella of Kaizen philosophy. These include 5S, Kaizen events, 5 Whys, Total Preventive Maintenance (TPM), and Just-In-Time (JIT) System (Chiarini et al., 2018). Others are the Suggestion System, Kaizen costing, Quality Circle (QC), Total Quality Management (TQM), Toyota Production System (TPS), Kanban system, elimination of Ohno’s seven wastes (Alvarado-Ramírez et al., 2017) and poka-yoke (error proofing) (Liker, 2004).

This study, however, focused on 5S, Kaizen events, 5 Whys, Total Productive Maintenance (TPM), Just-In-Time (JIT) Systems, Suggestion Systems, and Total Quality Management (TQM), as they are considered the major distinct practices in operational performance improvement (Titu et al., 2010). These systems, if well-coordinated and implemented, can lead to improvement in the efficiency and productivity of an organisation while ensuring a conducive organisational climate for continuous improvement and innovations (Titu et al., 2010).

1.2.3. Key performance indicators

Manufacturing operations performance management is characterised by four key distinct performance dimensions these are cost/productivity, time/speed, operations flexibility, and quality. Others include creativity, innovation, and customer satisfaction (Chiarini et al., 2018; McDermott et al., 2022). These four distinct classes of performance dimensions coincide with the four basic components of cost, quality, speed, and flexibility by which the manufacturing strategy of a firm is generally expressed (Garcia et al., 2018). Some of the purported human resource outcomes of the Kaizen event are increased employee knowledge of the need for improvement in the organisation (Singh & Singh, 2012), increased employee knowledge of the principles, tools, and techniques of continuous improvement, development of problem-solving skills (Nderi, 2012), and that it promotes teamwork in an organisation and proficiency in lean manufacturing tools (Garcia et al., 2018).

1.2.4. Challenges of Kaizen implementation

A comparative study in companies from Mexico and Ecuador by Alvarado-Ramírez et al. (2017) identified five barriers to the application of Kaizen, i.e. lack of involvement of all staff; restriction of resources (time, money, and personnel); lack of formal commitment and support by top management; lack of understanding of Kaizen and resistance to change. A study by Titu et al. (2010) as cited in Berhe (2021) observed that the main challenges of Kaizen implementation, particularly in Africa, are the lack of skilled workers and the lack of companies’ forward and backward integration to control business networks. Most people argue that Kaizen’s concept is new for many individuals (Titu et al., 2010). This view agrees with Garcia et al. (2018), who argued that a lower-skilled workforce represents the only obstacle to successful JIT implementation in developing countries and that this could be overcome through employee training.

In addition, Bulsuk (2011) is as cited in Berhe (2021) as having identified the following major challenges of Kaizen, especially in an emerging economy like Ethiopia: 1) Seeing Kaizen as a short-term project when the emphasis is on long-term improvement. 2) Tying Kaizen to KPIs with too much emphasis: 3) Implementing Kaizen in a heavily bureaucratic organisation 4) Lack of Management support and commitment.

However, to successfully implement Kaizen means that all employees need to be proactive and set aside time to make improvements and should be more than willing to contribute in any way possible (Murmura et al., 2021). This philosophy of continuous improvement can prove challenging. Numerous studies mention that, both in Japan and abroad, particularly in the cases of American and European companies, leadership is the single most significant aspect of the effective implementation of Kaizen (Alvarado-Ramírez et al., 2017). This suggests that it is plausible to apply Kaizen in countries with a variety of socio-cultural contexts; however, that application must be executed under the proper leadership and with changes that replicate the uniqueness of the targeted society (Bednarek & Ściborek, 2011).

On the transferability of Kaizen across cultures, there are views that question the general applicability of Kaizen to developing countries. They assert that most developing countries have to deal with the issue of weak human resources. Continuous improvement calls for a seamless extension of training and skills development for the entire labour force. A study by Anh et al. (2011) concluded that Kaizen practices could be transferable to non-Japanese cultural environments. However, the same study recommends that Kaizen practices should be adapted to the local culture; for them to have the highest probability of success (Anh et al., 2011).

Short-termism, the lack of upward mobility, and inattention to details of the workers, in general, may also add to difficulties in implementing Berhe (2021). Moreover, in nations where the hierarchical framework is seriously rooted, it might not be easy to establish a participatory mechanism in which nearly all workers are inspired to contribute actively to process and product improvements. Carnerud et al. (2018) showed empirically that an environment of worker participation is required if the benefits of 5S are to be reaped. In addition, managers’ misconceptions about continuous improvement are common sources of difficulty in Kaizen implementation since they often expect instant results. In reality, it takes time before the benefits of Kaizen become visible (Mano et al., 2014). In such circumstances, even if managers know the concept and tools, translating these ideas into practices and internalising Kaizen as a company-wide movement remains a very complex task.

Alvarado-Ramírez et al. (2017) found that the lack of organisational capabilities that facilitate an incremental organisation-wide innovation greatly hindered the implementation of Kaizen in Chinese firms. These capabilities include capabilities that facilitate cross-functional communication, encourages workers’ self-initiative, and discipline workers (shop-floor based) so that they conform to Kaizen standards. On-the-job training (OJT) plays a critical role in creating such capabilities. Employees in Japanese companies experience various kinds of jobs through the OJT, which helps to reduce the social distance between different categories of the workforce (Carnerud et al., 2018). In this perspective, organisational capabilities facilitate communication among diverse people, allowing Japanese companies to implement incremental organisation-wide innovation successfully. This affirms the view that the successful implementation of Kaizen is largely influenced by an organisation’s ability to develop these capabilities (Alvarado-Ramírez et al., 2017). Other capabilities are also important. Chen Hua Chung (2018) argue that larger firms enjoy larger financial and human resources, as well as economies of scale, and hence, have better conditions for the implementation of new techniques in their firms as compared to small or medium-sized firms.

1.2.5. Conceptual framework and hypotheses

Based on the review of the literature, the following conceptual framework about the Japanese management system, Kaizen, is developed. This conceptual framework is developed as indicated in Figure 1. When the manufacturing companies undertake Kaizen activities or practices in terms of 5S, Kaizen Events, 5Whys, Total Productive Maintenance, Just-In-Time, Suggestion System, and Total Quality Management, these practices lead to improved operations performance in terms of Quality, Productivity, Speed, Flexibility and Overall Equipment Effectiveness.

Figure 1. Conceptual framework of Kaizen practices and operational performance.

1.3. S and operational performance

The Kaizen management system reduces losses based on process improvement and labour productivity instead of investment (Titu et al., 2010). The Kaizen 5S method provides an opportunity to increase efficiency and productivity by providing a pleasant organisational atmosphere. According to Titu et al., Kaizen activities should be carried out daily. The direct result will be finding innovative ways to eliminate waste, redesign the workplace, and make each employee’s job easier. Titu et al. (2010) conducted a study on 5S in the after-sales department of an automotive service workshop. After implementing the 5S steps, the service workshop can more easily identify problems that complicate sales and service operations.

In a study of Kenyan manufacturing firms, Nderi (2012) showed a strong relationship between improving operational efficiency and implementing Kaizen (5S) practices related to productivity, quality, speed, flexibility, and overall equipment efficiency. Further, a report by the Kenya Manufacturers Association shows that Kaizen activities have the expected impact on various aspects of production, resulting in a 50–70% reduction in lead time, a 50–100% increase in productivity, and a 20–40% savings in production costs. It has also been reported that there has been a 40–60% reduction in quality defects and 50% redundancy in the workplace, as well as a significant improvement in team spirit and overall morale (Kenya Association of Manufacturers, 2012). From the above results, the Kenya Manufacturers Association concluded that the different levels of implementation of Kaizen practices produce corresponding degrees of achievement in firms, with 5S having the most effective performance and suggestion system and TPS having the minor extent of implementation.

A study on the effects of the new Kaizen technique introduced in three pilot companies in northern Ethiopia (an engineering company, a textile factory, and a tannery) found that the three pilot companies reduced costs, improved quality, lead time, and customer satisfaction (Desta et al., 2014). Further, the companies had achieved three of the five Kaizen 5s steps: organise, adjust, and polish, but they still needed to achieve standardisation and self-discipline sustainability. The above arguments lead to the following hypotheses:

Hypothesis 1a: Kaizen practices (5S) positively correlate with Productivity in Zambian manufacturing companies.

Hypothesis 1b: Kaizen practices (5S) positively correlate with Quality in Zambian manufacturing companies.

Hypothesis 1c: Kaizen practices (5S) positively correlate with Speed in Zambian manufacturing companies.

Hypothesis 1d: Kaizen practices (5S) have a positive relationship with Flexibility in Zambian manufacturing companies.

Hypothesis 1e: Kaizen practices (5S) positively correlate with Overall Equipment Effectiveness in Zambian manufacturing companies.

1.4. Whys and operational performance

In the 1930s, Sakichi Toyo developed a problem-solving method that asked, “Why?” After repeating it five times, the nature of the problem and the solution become clear. From a pedigree perspective, 5-whys traces its roots to the Toyota Production System (TPS). (Ohno, 1988).) It also plays a vital role in Lean (Zidel, 2006; a general version of TPS). Taiichi Ohno describes the 5 whys as the center for TPS methodology.

Murugaiah et al. (2010) documented an approach to reducing scrap losses using root cause analysis in a high-volume manufacturing environment. This research uses the method of high production root problem solving (RCPS). The study begins with the collection stage, followed by the analysis stage and the solution stage. Supporting information is provided through a Pareto chart to prioritise waste to focus more on improvement. A 5-whys analysis of the Toyota production system was conducted to analyse the causes of waste and formulate and implement corrective actions. Applying 5-why analysis in manufacturing provides a fact-based and structured approach to problem identification and correction.

Benjamin et al. (2015) show how applying the 5-why analysis attacks the OEE productivity loss category. In particular, they show how a 5-why analysis can be used in practice to determine OEE rates. The 5-whys analysis method has proven to be the most effective method to solve and eliminate the most critical losses among all types of OEE losses. They are removing low-speed losses resulting in annual savings of $32,811.50 for a company that is part of a group of companies based in Malaysia and Europe.

Braglia et al. (2017) report a novel Single-Minute Exchange of Die (SMED) set-up reduction approach, fully integrated with a 5-Whys Analysis. It permits highlighting not-optimized conditions from the changeover perspective to reduce the SMED activity’s effort and cost. Indeed, all set-up losses are investigated structurally to identify their root causes and all possible interactions, thus suggesting better interventions in terms of efficiency. This way, the analyst is supported and facilitated while defining the actions required to reduce the set-up times. In particular, the “why-why analysis” implementation is supported and integrated with (i) a general schematization of the generic workstation and (ii) an active worksheet that leads the analyst through the investigation of the machine and its set-up process. Thus, we propose the following hypotheses:

Hypothesis 2a: Kaizen practices (5 Whys) have a positive relationship with Productivity in Zambian manufacturing companies.

Hypothesis 2b: Kaizen practices (5 Whys) have a positive relationship with Quality in Zambian manufacturing companies.

Hypothesis 2c: Kaizen practices (5 Whys) have a positive relationship with Speed in Zambian manufacturing companies.

Hypothesis 2d: Kaizen practices (5 Whys) have a positive relationship with Flexibility in Zambian manufacturing companies.

Hypothesis 2e: Kaizen practices (5 Whys) have a positive relationship with Overall Equipment Effectiveness in Zambian manufacturing companies.

1.4.0.1. Kaizen events and operational performance

Kaizen events are a way to focus on improving existing processes. This typically involves gathering front-line employees, managers, and stakeholders involved in specific operations, mapping existing processes, soliciting ideas for changes to solve the problem, and then implementing improvements (Letens et al., 2006). Kaizen events have been widely reported to produce positive changes in business and human resource outcomes (Chittipaka & Lalitha, 2012). Specifically, Kaizen events are related to implementing lean production.

The philosophy of Kaizen Event is based on the idea that everything can be improved, that slight improvement can produce significant results, and that incremental improvement must be made consistently. Many companies have adopted this philosophy and made rapid but significant improvements in almost all areas of their operations (Brunet & New, 2003). Habidin et al. (2016) developed a model linking Kaizen Event to performance in the Malaysian automotive sector. The model, when tested, found a positive relationship between Kaizen Event implementation and SME performance in the automotive industry in Malaysia.

In India’s automotive spare parts industry, Kaizen Event carried out on the hydraulic actuator produced benefits such as reduced cycle time, reduced operator fatigue, reduced quality, accommodated new designs, and increased operator confidence and morale (Shettar et al., 2015). Also, in five large-scale automotive manufacturing organisations located in the Chennai region of India, Chittipaka and Lalitha (2012) found Indicators of Kaizen events, i.e., participation in decision-making, communication and respect for top management, employee involvement, training and education, and perceived quality performance are identified to be more strongly associated with project improvement sustainability outcomes. Thus, we propose the following hypotheses:

Hypothesis 3a: Kaizen practices (Kaizen Events) have a positive relationship with Productivity in Zambian manufacturing companies.

Hypothesis 3b: Kaizen practices (Kaizen Events) have a positive relationship with Quality in Zambian manufacturing companies.

Hypothesis 3c: Kaizen practices (Kaizen Events) have a positive relationship with Speed in Zambian manufacturing companies.

Hypothesis 3d: Kaizen practices (Kaizen Events) have a positive relationship with Flexibility in Zambian manufacturing companies.

Hypothesis 3e: Kaizen practices (Kaizen Events) have a positive relationship with Overall Equipment Effectiveness in Zambian manufacturing companies.

1.4.0.2. Total productive maintenance and operational performance

TPM stands for “Total Productive Maintenance” and establishes a close relationship between Maintenance and Production, suggesting that good maintenance and upkeep will lead to high productivity. The main objective of TPM is to maximize overall equipment efficiency by eliminating or reducing losses. The purpose of productive maintenance is to improve plant and equipment efficiency to achieve optimal life cycle costs for production equipment. Therefore, the benefits of TPM include productivity and OEE (Overall Equipment Effectiveness). TPM requires motivation and inspiration from the workforce to be successful and effective (Nakajima, 1988). TPM generally reduces six losses—equipment failure, downtime, setup time, work defects, low productivity, and slow speed (Macaulay, 1988).

A study of Indian pharmaceutical manufacturers found that TPM practices significantly impacted factory-level performance (Modgil & Sharma, 2016). Another study by Van der Wal and Lynn (2002) looked at implementing productive maintenance (TPM) in a South African factory. It sought to determine the impact of this journey on productivity, employee development, quality improvement, and organizational change. The success of this journey led to increased productivity, improved quality, and reduced manufacturing costs, earning the mill a Gold Award from the National Institute of Manufacturing.

Through the example of TPM implementation in an electronics manufacturing company, Chan et al. (2005) found that both tangible and intangible benefits for equipment and personnel are shown after applying the TPM model. The engine performance of the model increased by 83%. Another example of implementing TPM in such an environment is a high-precision manufacturing plant in mainland China. The factory adopted a three-phase program to implement the change. The first two phases of the program have been completed, with significant productivity improvements (Tsang and Chan (2000). The above arguments lead to the following hypotheses:

Hypothesis 4a: Kaizen practices (TPM) have a positive relationship with Productivity in Zambian manufacturing companies.

Hypothesis 4b: Kaizen practices (TPM) have a positive relationship with Quality in Zambian manufacturing companies.

Hypothesis 4c: Kaizen practices (TPM) have a positive relationship with Speed in Zambian manufacturing companies.

Hypothesis 4d: Kaizen practices (TPM) have a positive relationship with Flexibility in Zambian manufacturing companies.

Hypothesis 4e: Kaizen practices (TPM) have a positive relationship with Overall Equipment Effectiveness in Zambian manufacturing companies.

1.4.0.3. JIT and operational performance

The concept of the Just-In-Time (JIT) system is used by Japanese managers and used in manufacturing and service companies and was introduced by Shigeo Shingo and Taichi Ohno at Toyota Motor Company. JIT emphasises eliminating waste and optimising the use of resources in the supply chain. JIT integrates all purchasing, manufacturing, and supply operations in the supply chain. This integrated process should lead to the lowest level of inventories in the organisation and several improvements in various areas, such as speed of supply, reliability, responsiveness, and flexibility (Green et al., 2014). Consistent with these assertions, some studies show the positive impact of JIT on operational performance.

Phan et al. (2019) presented the results of an empirical study that investigated the relationship between total quality management (TQM) practices, just-in-time (JIT) manufacturing practices, and flexibility in manufacturing companies in 12 countries including China, Finland, Germany, Italy, Israel, Japan, Korea, Spain, Sweden, Taiwan, England, and Vietnam as part of the High-Performance Manufacturing Project from 2013 to 2015. Results confirm the closed relationship between TQM, JIT manufacturing practices, and flexibility performance. Furthermore, this study shows that a high level of TQM practices can enhance the impact of JIT manufacturing practices on flexibility performance. The main results of this study show that flexibility performance can be built through the implementation of TQM and JIT manufacturing practices, and TQM should be considered a platform to improve the impact of JIT manufacturing on flexibility performance. Among suppliers in the automotive industry in Malaysia, Osman et al. showed that JIT purchasing and JIT manufacturing have direct and significant benefits on logistics performance.

A study by Chen (2015) investigating the relationship between (JIT) manufacturing and production operations performance among Chinese manufacturing companies showed a positive relationship between JIT and production operations performance. Terna, Iorhen Peter, 2014) also confirmed the positive relationship between JIT and the organisational performance of more than 2,000 Zarab Company employees. In addition, two studies from Jordan provide evidence of the effect of JIT on operational performance. Al-Haraisa (2017) found that JIT management positively affected the performance of Jordanian industrial companies operating at the Al—Hussein bin Abdullah II qualified industrial zone (QIZ) in Al-Karak Governorate. While Zaid et al. (2016), who investigated the impact of total just-in-time (T-JIT) supply chain management practices (buying, manufacturing, and selling) on operational performance in terms of organizational capabilities involving 166 industrial companies in Jordan, found that JIT manufacturing affects both; JIT buying and JIT selling. Further, the results show that JIT selling directly affects operational performance, while JIT production has an indirect effect through JIT selling. The above arguments lead to the following hypotheses:

Hypothesis 5a: Kaizen practices (JIT) have a positive relationship with Productivity in Zambian manufacturing companies.

Hypothesis 5b: Kaizen practices (JIT) have a positive relationship with Quality in Zambian manufacturing companies.

Hypothesis 5c: Kaizen practices (JIT) have a positive relationship with Speed in Zambian manufacturing companies.

Hypothesis 5d: Kaizen practices (JIT) have a positive relationship with Flexibility in Zambian manufacturing companies.

Hypothesis 5e: Kaizen practices (JIT) have a positive relationship with Overall Equipment Effectiveness in Zambian manufacturing companies.

1.4.0.4. Employee suggestion systems and operational performance

Suggestion systems are integral to employee-oriented kaizen strategies and have shown benefits in improving employee morale and engagement (Masaaki, 2013). The ideas and suggestions of employees are an essential contribution to the improvement and productivity of the organisation, but this can only be achieved when the organisation adopts a kaizen culture, a system to generate creative ideas from employees involved and valued for the improvement of the organisation (Iorhen et al., 2021).

Therefore, the ideas generated by employees and created by employees using the suggestion system are beneficial for the organisation. Employee recommendations to deploy modern technology and equipment for operations, attract more competitive suppliers, reduce costs, and leverage organisational resources. As long as employees continue to contribute ideas and suggestions, there is continuous improvement in operational processes, procedures, and methods for quality products and services (Iorhen et al., 2021).

Moica et al. (2018) showed the significant impact of the suggestion system adopted by an Austrian car company. An essential feature of this company is the efficiency of the Lean Production System implementation. The company has created a personalised model and continues to develop it with its employees. Managers focus on and support the professional and personal development of employees. Moika et al. studied the suggestion system to examine the relationship between overall performance and the number of improvement ideas implemented during the first six years after 2011. Research shows a close relationship between the number of ideas and productivity.

From the discussion above, the following hypotheses are proposed:

Hypothesis 6a: Kaizen practices (Suggestion Systems) have a positive relationship with Productivity in Zambian manufacturing companies.

Hypothesis 6b: Kaizen practices (Suggestion Systems) have a positive relationship with Quality in Zambian manufacturing companies.

Hypothesis 6c: Kaizen practices (Suggestion Systems) have a positive relationship with Speed in Zambian manufacturing companies.

Hypothesis 6d: Kaizen practices (Suggestion Systems) have a positive relationship with Flexibility in Zambian manufacturing companies.

Hypothesis 6e: Kaizen practices (Suggestion Systems) have a positive relationship with Overall Equipment Effectiveness in Zambian manufacturing companies.

1.4.0.5. TQM and operational performance

TQM practices generally improve organizational performance (Sadikoglu & Olcay, 2014). TQM practices help improve customer satisfaction with the participation of all employees; productivity and customer satisfaction are critical themes for organizational success. To create this value, organisations are designed to create value and operational performance (Kim et al., 2015). Improving operational performance leads to lower costs and greater customer satisfaction. Therefore, every business requires operational success to determine survival in a competitive world (Pradhan, 2017). In addition, TQM practices are essential to achieve a smooth supply chain that will significantly impact optimal performance (Sharma & Modgil, 2019). Several studies have shown the importance of TQM practices on operational performance and are discussed below.

A research instrument was developed to examine three relationships between TQM practices, supply chain management (SCM) practices, and the productivity of pharmaceutical manufacturing plants in India. During the testing of alternative models, it was observed that TQM practices have a direct impact on operational performance. However, TQM practices directly affect supply chain components, which also affect overall performance. Compared to alternative models, models, where TQM practices have a more significant impact on supply chain practices and supply chain performance are considered more relevant (Sharma & Modgil, 2019).

A 1994 survey of manufacturing site managers conducted by the Australian Manufacturing Council (AMC) in association with the Australian Bureau of Statistics and the Manufacturing Advisory Group (New Zealand) showed the importance of the relationship between TQM practices and organisational performance (Samson & Terziovski, 1999).

The results of a Tunisian study on the effects of TQM in several selected manufacturing firms show that several companies that implement TQM can improve quality or productivity by using existing techniques and equipment were 9 out of 14 (64%) in the electrical and electronics industry, and the food industry 4 out of 13 (31%). For example, eight companies achieved at least 20% higher productivity, 3 of which increased productivity by at least 50%. Another company reduced non-conformance rates from 20% to 0%, and another reduced die replacement downtime from 110 minutes to 70 minutes (Fiorillo et al., 2021). Therefore, TQM tools (Value Flow Map and Ishikawa Diagram) identify waste and inefficiencies and improve operational performance by implementing corrective actions.

A study conducted in Turkey to investigate the impact of TQM practices on various performance measures found that TQM was significantly and positively related to organisational performance. Another study examined the extent of TQM practices implemented in Palestinian hospitals and their relationship with organisational performance using the Malcolm Baldrige National Quality Award (MBNQA) criteria. Research results show that the TQM construct, namely MBNQA, has a positive relationship with hospital performance, and that relationship was, for the most part, significant (Sabella et al., 2014).

In Bangladesh, TQM has been piloted for the jute sector under the title “Study on Industrial Development Potential for Export Diversification.” After six months, the four model companies achieved an average 11% increase in production in their spinning units and a 45.7% reduction in machine downtime. In the textile unit, there was a 13.4% increase in output and a 23.5% reduction in machine maintenance (JICA and UNICO International Corporation, 2009). In addition, a study by Berhe (2021) in Ethiopia found that manufacturing companies implementing TQM practices can increase productivity by using existing techniques and equipment. Findings demonstrate TQM’s experience in achieving monetary, non-monetary, and quality outcomes. However, the results vary from company to company. Productivity, production volume, machine productivity, and sales volume increased on average by 2.77%, 28.69%, 10.14%, and 31.53%, respectively.

From the discussion above, the following hypotheses are proposed:

Hypothesis 7a: Kaizen practices (TQM) have a positive relationship with Productivity in Zambian manufacturing companies.

Hypothesis 7b: Kaizen practices (TQM) have a positive relationship with Quality in Zambian manufacturing companies.

Hypothesis 7c: Kaizen practices (TQM) have a positive relationship with Speed in Zambian manufacturing companies.

Hypothesis 7d: Kaizen practices (TQM) have a positive relationship with Flexibility in Zambian manufacturing companies.

Hypothesis 7e: Kaizen practices (TQM) have a positive relationship with Overall Equipment Effectiveness in Zambian manufacturing companies.

1.5. Operationalisation of the concepts in the hypotheses

The concepts were operationalised as follows:

1.5.1. Kaizen practices

This study measured seven practices of Kaizen: 5S, Kaizen events, 5whys, total productive maintenance, Just-In-Time, systems, suggestion system, and total quality management. Respondents were asked to rate the extent to which the company had implemented the Kaizen practices. This was measured by using a 5-point Likert Scale, from 1- Minimal to 5- a great extent.5S- A way to visualise the working place, assuming the care of the workplace, on the basis of: selection, systematic, cleaning, standardisation, and self-discipline (Chiarini et al., 2018).

Total Productive Maintenance (TPM)-Actions improving the continuous maintenance of machinery by preventing accidents and downtime. An indirect measure of the effectiveness of total production maintenance is the Overall Equipment Efficiency (OEE) which is the degree of effective use of equipment, measured as a percentage.

Suggestion Systems- is an approach by which the suggestions and ideas of the employees are conveyed all the way upward through the management hierarchy (Marin-Marin-Garcia et al., 2018). Just-In-Time (JIT)—is producing and supplying goods at the time they are needed. The company holds the minimum number of raw materials and just enough finished products to meet demand.

Kaizen Events- are a focused, short-term project to improve a process. It includes training followed by an analysis, design, and, often, re-arrangement of a product line or area; or are short-duration improvement projects with a specific aim for improvement; typically, they are weeklong events led by a facilitator with the implementation team being predominantly members of the area in which the kaizen event is being conducted plus a few additional people from support areas and even management.

5 Why’s- the practice of asking, five times, why the failure has occurred in order to get to the root cause or causes of the problem; and can be a lot more than one particular cause of a problem as well.

Total Quality Management (TQM)—a set of systematic activities carried out by the entire organisation to effectively and efficiently achieve company objectives to provide products and services with a measure of quality that meets customers at the ideal time and price (Berhe, 2021; Carnerud et al., 2018).

1.5.2. Operational performance

This study measured operations’ performance in terms of quality, cost or productivity, speed, and flexibility. The respondents were asked to rate the improvement in the performance dimensions. Measurement of improved operations’ performance consisted of a 5-point scale, where 1(Minimal) (1) and 5 (Great Extent). Productivity—an index that measures output (product) relative to the input (labour, materials, or energy used to produce the output). This is also the overall measure of the ability to produce a product. Quality—a real measure of excellence or a condition of being relieved from flaws, inadequacies, and extensive variations. Having a strict and consistent commitment to specific standards that achieve uniformity of a product to satisfy the specific customer or user requirements. Speed—the rate at which production flows. This reduces inventory, increases liquidity, reduces risk (uncertainty about the future), and creates a competitive advantage. Flexibility—the capacity to produce a product in a variety of ways. This saves time and costs, maintains dependability, and speeds-up response to customer needs. Overall Equipment Effectiveness—is a measure of the entire (complete, whole, inclusive) equipment performance- the extent to which the tool is carrying out what it is intended to do (Berhe, 2021; Alvarado-Ramírez et al., 2018).

1.6. Methodology

1.6.1. Research design

The study employed a cross-sectional research design to determine the relationship between the variables- Kaizen practices and operations’ performance. The sampling design was the census. This was influenced by the relatively few companies that had implemented Kaizen in manufacturing industries in Zambia.

1.6.2. Population and sampling

In 2002, the government of the Republic of Zambia conducted a manufacturing survey which established that a high concentration (about 67%) of manufacturing companies were in Lusaka Province and Copperbelt Province (GRZ, 2014). Hence, the targeted population was the manufacturing companies in Lusaka Province and Copperbelt Province that had adopted and implemented the Kaizen philosophy or concept. The Zambia Association of Manufacturers (ZAM) and Kaizen Institute in Zambia (KIZ) listed 33 companies that had implemented Kaizen in Zambia (Kaizen Institute of Zambia (KIZ) News Letter No. 3, 2015). This formed the target population for the study. Questionnaires were distributed to all thirty-three (33), but only thirty-one (31) companies returned the fully answered questionnaires.

1.6.3. The questionnaire

The primary data for the study was collected towards the end of 2015 using structured questionnaires which were administered to managers, operational managers, or equivalent managers of manufacturing companies practising Kaizen in Lusaka Province and Copperbelt Province. The questionnaire was developed based on inputs from the literature. The questionnaire comprised a five-point Likert scale that collected the respondents’ responses to both operational performance items as well as Kaizen practices quantitatively through closed-ended questions. Also, the questionnaire consisted of four sections. Section 1 explored the respondents’ company profiles. Section 2 assessed respondents’ responses on the extent of Kaizen practices implementation. Section 3 investigated the respondents’ evaluation of manufacturing companies’ improved operational performance dimensions. Section 4 talked about Kaizen implementation challenges faced by companies.

Prior to collecting the data, the items on the questionnaire were pretested with two academicians (from the operations and supply chain management discipline) and two executives at the Kaizen Institute of Zambia. Also, a pilot study was conducted with 6 executives from the manufacturing companies that have implemented Kaizen in the Copperbelt Province to assess the research instrument’s quality. These steps resulted in some changes being made, mainly to improve the clarity of the questions. The questionnaires were physically distributed to the thirty-three participating companies, and after one week, a follow-up was made to collect completed questionnaires.

1.7. Data analysis and findings

1.7.1. Response rate and demographic data

The study distributed questionnaires to Managers and Operational Managers. Of thirty-three (33) questionnaires distributed, thirty-one (31) were completed by the respondents and collected, while two were not returned. This represented a response rate of 93.9 %, which was a very good rate.

The data revealed that the respondent companies with less than 50 employees were 9 (29%), between 51 and 100 employees were 8 (25.8%), between 101 and 150 employees were 5(16.1%), between 151 and 200 employees were 3 (9.7%); and more than 200 employees were 6(19.4%). The sectoral representation of thirty-one manufacturing companies was roughly evenly spread among 6 sectors. The data revealed that 9 (29%) were in food and beverages, 3 (9.7%) came from the textiles and leather industries, 5 (16.1%) were in chemical, rubber, and plastics products, and another 5 (16.1%) were in basic metal products, 4 (12.9%) came from the fabricated metal products sector, and 5 (16.1%) came from other sectors.

1.7.2. Challenges faced by companies in Kaizen implementation

Respondents were asked to give their perceptions on the extent to which they felt their firms experienced challenges on nine mostly experienced challenges by companies implementing Kaizen using a 1–5 scale with 1 (Not at all) and 5 (To a great extent). Table 1 below shows that employee attitude was the most challenging the companies faced with a mean of 3.19. This was followed by financial constraints and insufficient participation by workers with a mean of 2.71, respectively. Ineffective training was third with a mean of 2.55, and misconceptions about Kaizen had a mean of 2.52. Ineffective Kaizen Performance measures had a mean of 2.43, Organisation Structure had a mean of 2.42, and Ineffective Communication Systems had a mean of 2.26. The least was a Lack of Management Support or Leadership with a mean of 2.16.

Table 1. Summary of respondent demographics

Length of Service of Respondents	n	%
Less than two years	4	12.90
Two to five years	12	38.7
Six to ten years	7	22.6
More than ten years	8	25.8
Number of Employees in Respondent Companies
Less than 50 employees	9	29
Between 51 and 100 employees	8	25.8
Between 101 and 150 employees	5	16.1
Between 151 and 200 employees	3	9.7
More than 200 employees	6	19.4
Sectoral Representation of Respondent Companies
Food and beverages	9	29
Textile, and leather industries	3	9.7
Chemical, rubber and plastics products	5	16.1
Basic metal products	5	16.1
Fabricated metal products	4	12.9
Others	5	16.1

The results indicate that the companies could do better if employee attitude was to change as management support or leadership did not seem to be a serious challenge. These results are consistent with findings by Chen Hua Chung (2018) on organisational capabilities that facilitate Kaizen implementation; Anh et al. (2011) on the difficulties of misconceptions about Kaizen in its implementation as well as Marzec (2013) on the importance of training and skills development in the implementation of continuous improvement methodologies such as Kaizen. The financial constraints also posing a lesser challenge to Kaizen implementation are consistent with arguments that Kaizen is a low-cost approach to process improvements and it involves the employees or workers Berhe (2021).

The results reveal that employees’ attitude was the most serious challenge the companies were facing, followed by financial constraints, insufficient participation by workers, ineffective training, misconceptions about Kaizen, ineffective Kaizen performance measures, organisation structure, and ineffective communication systems. The least was the lack of management support or leadership and other unspecified areas.

1.7.3. Measurement of reliability and validity

The study addresses twelve primary constructs related to Kaizen events, 5 Why’s Total Productive Maintenance (TPM), Just-In-Time (JIT) Systems, Suggestion System and Total Quality Management (TQM), quality, productivity, speed of operations (Speed), the flexibility of operations (Flexibility) and Overall Equipment Effectiveness. Existing scales from the literature were used for all the constructs. Descriptive statistics, factor analysis, and scale reliabilities are provided in Table 2. The scale reliability for the Flexibility factor was 0.538, which was poor according to the rule of thumb of 0.700 suggested by George and Mallery (2003). Thus, the Flexibility factor was not included in the subsequent analysis.

Table 2. Means of responses to challenge of Kaizen implementation

Mean	Mean
Financial constraints	2.71
Lack of management support or leadership	2.16
Ineffective training	2.55
Employee attitude (e.g commitment)	3.19
Ineffective kaizen performance measures	2.43
Insufficient participation by workers	2.71
Ineffective communication systems	2.26
Organisation Structure	2.42
Misconceptions about kaizen	2.52
Others	2.03

In addition, a test of discriminant validity is reported in Table 3. Furthermore, Hair et al. (2014) suggest that the shared variance between multi-item scales is compared to the reliability of each scale. In all cases, the reliability estimates for the one-dimensional constructs were greater than the shared variances of the pairs, verifying discriminant validity for the constructs (Field, 2009).

Table 3. Scale items: Descriptive statistics, factor analysis and Cronbach’s (Coefficient) alpha

Construct (Coefficient α)	Factor	Mean	Standard Deviation	Factor Loadings
5S α = .859	5S1: Sorting 5S2: Order 5S3: Cleanliness 5S4: Standardization 5S5: Self-discipline	3.96 4.09 4.19 3.93 3.90	.94 .87 .70 1.09 .94	.891 .917 .625 .867 .686
Kaizen Evens α = .781	Kaizen Event1: Short term interventions Kaizen Event2: Improving existing processes Kaizen Event3: Target work area by the team	3.58 4.00 4.03	.95 .77 .94	.826 .888 .805
5Whys α = .835	5Whys1: Problem identified 5Whys2: Asking five times on problem 5Whys2: Problem root cause found	3.83 3.41 3.80	1.12 1.33 1.10	.899 .796 .923
Suggestion System α = .800	Suggestion1: Specific system used e.g., box Suggestion2: Employees know hierarchy Suggestion3: Immediate feedback provided	3.51 3.80 3.64	1.45 1.04 1.17	.801 .848 .914
Total Productive Maintenance (TPM) α = .808	TPM1: Routine maintenance done TPM2: Self-equipment maintenance TPM3: Effective equipment use	3.87 3.64 3.84	1.15 1.14 .93	.896 .786 .879
Total Quality Management (TQM) α = .800	TQM1: Uses number of practices TQM2: Interacts with customers TQM3: Involves all employees	3.68 4.13 4.06	1.04 .88 .81	.818 .831 .892
Just-in-Time (JIT) α = .755	JIT1: Products delivered on time JIT2: Holds enough raw material JIT3: Holds enough products	3.77 3.84 3.87	1.17 1.13 1.15	.665 .818 .871
Productivity α = .793	Productivity1: Reduced idle time Productivity2: Ensured health and Safety Productivity3: Reduced costs	3.61 4.16 3.71	.84 .82 .86	.896 .815 .813
Quality α = .851	Quality1: Free from defects Quality2: Reduced customer complaints Quality3: Sticking to set standards	3.90 4.03 4.35	.83 .795 .84	.850 .751 .835
Speed α = .836	Speed1: Improved production flow Speed2: Reduced inventory Speed3: Reduced future uncertainty	3.90 3.58 3.55	1.01 .92 .92	.886 .885 .832
Flexibility α = .538	Flexibility1: Product produced in different ways Flexibility2: Speeded-up response to customer needs Flexibility3: Customers’ dependability on company products	3.26 4.03 4.26	1.26 .875 .815	.564 .930 .712
Overall Equipment Effectiveness α = .825	OEEffectiveness1: Equipment availability OEEffectiveness1: Improved performance efficiency OEEffectiveness1: Improved quality of product	4.06 3.84 4.26	.93 .90 .68	.889 .893 .804

1.7.4. Findings

Seven summated indexes of the Kaizen practices were created based on the items on each practice, with each item being evenly weighted. Descriptive statistics of these summated Kaizen practices were used to assess the extent to which the thirty-one companies had implemented the seven Kaizen practices (see, Table 4 below). The results showed that 5S had the greatest extent of implementation with a mean of 4.01, Total Quality Management second with 3.96 and Kaizen Events third with 3.90, Just-in-time fourth with 3.78, Total Productive Maintenance fifth with 3.72 and 5 Whys sixth with 3.70. The Suggestion System was the least in the extent of implementation with a mean of 3.60. The results are displayed in Table 4 below.

Table 4. Test for construct discriminant validity

	1	2	3	4	5	6	7	8	9	10	11
Scale Reliability	.859	.781	.835	.800	.808	.793	.755	.793	.851	.836	.825
Construct shared variance
5S	1
Kaizen Events	.595	1
5 Whys	.616	.643	1
Suggestion System	.683	.620	.729	1
Total Productive Maintenance (TPM)	.742	.563	.618	.732	1
Total Quality Management (TQM)	.759	.560	.723	.712	.727	1
Just-In-Time (JIT)	.607	.439	.601	.437	.561	.677	1
Productivity	.468	.583	.612	.484	.454	.627	.598	1
Quality	.511	.596	.577	.469	.533	.433	.420	.569	1
Speed	.536	.361	.487	.484	.641	.595	.683	.500	.459	1
Overall Equipment Effectiveness	.542	.566	.544	.599	.535	.423	.456	.527	.681	.590	1

The hypotheses were tested using multiple linear regressions using four models. Due to the small sample size (31), only three independent variables were used (the three that had the greatest extent of implementation). Thus, the independent variables for the four models were the following factors: 5S, Kaizen Events, and Total Quality Management. The first model had productivity as the dependent variable, and models 2, 3, and 4 had Quality, Speed, and Overall Equipment Effectiveness as dependent variables, respectively. The study included firm size as a control variable because firm size has become a routine control variable in empirical studies (Kurshev & Strebulaev, 2015). Larger firms tend to have more resources than smaller firms which may influence the implementation of Kaizen in a firm. The number of employees in a firm was used as a proxy for firm size.

As a first step in testing the hypotheses, the study used hierarchical regression. All variables were standardised to reduce the potential effects of multi-collinearity (Cohen et al., 2003). The technique of least squares was used with the control variable Firm Size entered as a block in step 1, followed by the main effects in step 2 (5S, Kaizen Events and Total Quality Management). The normality assumption for the residuals is indicated in Figure 2

Figure 2. Histograms testing for normality assumption.

Table 5 presents the results of the testing of Hypotheses 1a-e,3 a-eand7a-e. The first column in the Table 6 shows the relevant independent variables, while the corresponding right-side columns display the effect size (standardised b) and significance (t-value) of each direct relationship. As shown in row two at step 2 of the table, Hypothesis 1a, 1b, 1c, and 1e related to 5S are not supported. 5S activities are not significantly associated with Productivity (b = −0.151; t = −0.663); Quality (b = 0.264; t = 1.065); Speed (b = 0.238; t = 0.957) and Overall Equipment Effectiveness (b = 0.349; t = 1.402). Three hypotheses, H 3a, H3b, and H3e, related to Kaizen Events have been supported. Kaizen Events are significantly associated with Productivity (b = 0.360; t = 1.999); Quality (b = 0.438; t = 2.235); and Overall Equipment Effectiveness (b = 0.405; t = 2.058). However, hypothesis H 3c was not supported. Kaizen Events are not significantly associated with speed (b = −0.042; t = −0.215).

Table 5. Mean of responses on extent of Kaizen practices implementation

Kaizen Practice	Mean	Std Dev
5S	4.01	0.74
Kaizen Events	3.90	0.75
5Whys	3.70	1.04
Suggestions Systems	3.62	1.04
Total Productive Maintenance	3.72	0.92
Total Quality Management	3.96	0.77
Just—In-Time	3.78	0.94

Table 6. Examination of direct effects

		Productivity		Quality		Speed		Overall Equipment Effectiveness
Independent Variable	Hypothesis (Result)	Std β	t	Std β	t	Std β	t	Std β	t
Step 1: Control variables
Firm size (SIZE)		0.329	1.877*	0.234	1.298	0.320	1.818	0.073	0.396
R-Squared			0.11		0.06		0.10	0.01
Model Fit		F = 3.524		F = 1.686		F = 3.306*		F = 0.157
Step 2: Main Effects
Firm size (SIZE)		0.107	0.716	0.083	0.509	0.172	1.062	−0.083	−0.509
5S		−0.151	−0.663	0.264	1.065	0.238	0.957	0.349	1.402
Kaizen Event	3a 3b 3e (Support)	0.360	1.999*	0.438	2.235**	−0.042	−0.215	0.405	2.058**
Total Quality Management	7a (Support)	0.509	2.259**	−0.037	−0.151	0.386	1.571	−0.044	−1.78
R-Squared			0.49		0.40		0.40	0.39
Model Fit	Hypothesis	F = 6.320***		F = 4.316***		F = 4.276***		F = 4.22***

***p < 0.01; **p < 0.05; *p < 0.10.

As for Total Quality Management, only one hypothesis, H 7a, was supported, whilst hypotheses H 7b, H 7c, and H 3e were not supported. Total Quality Management is significantly associated with Productivity (b = 0.509; t = 2.259) but not significantly associated with Quality (b = −0.037; t = −0.151); Speed (b = 0.386; t = 1.571) and Overall Equipment Effectiveness (b = −0.044; t = −0.178). These results imply that Total Quality Management has more influence on Productivity than Kaizen Events and 5S. The results also indicate that Kaizen Event has more influence on quality than 5S and Total Quality Management. Furthermore, the results indicate that Kaizen Event has more influence on Overall Equipment Effectiveness than 5S and Total Quality Management. None of the three variables was significantly associated with the speed of operations (Speed).

Regarding the control variable, the results showed that Firm Size did not have statistically significant effects on Quality, Speed, and Overall Equipment Effectiveness. However, it did have a significant effect, albeit a weak one (p < 0.10), on productivity.

1.8. Discussion

1.8.1. Productivity

Kaizen Events and Total Quality Management were significantly related to productivity. These results are consistent with findings from the literature. McDermott et al. (2022) also found a strong link between Kaizen practices and improved performance in the MedTech industry. In addition, studies conducted in Ethiopia by Berhe (2021) found that manufacturing companies that implemented Kaizen practices were able to improve productivity using existing machinery and equipment. However, Kaizen and 5s showed no significant relationship to productivity which is inconsistent with the findings from the literature.

1.8.2. Quality

Kaizen events were significantly related to quality. The result is consistent with the findings from the literature. A study conducted in the agriculture sector showed that there is a link between kaizen practices and improvement in performance (McDermott et al., 2022). Furthermore, studies conducted by Berhe (2021) in Ethiopia, Nderi (2012) in Ethiopia all showed that Kaizen techniques, when implemented, improved quality. However, kaizen 5S and total quality management were not significantly related to quality. These results are not consistent with the findings from the literature.

1.8.3. Speed

Kaizen 5S, Kaizen events, and total quality management showed no significant relationship to speed. These findings are not consistent with the results from the literature. For example, studies done in India on manufacturing firms show that most manufacturing industries are currently encountering a necessity to quickly respond to rapidly changing customers’ needs, tastes and desires through continuous improvements (Singh & Singh, 2012). Additionally, studies by Marzec (2013) on a casting-based manufacturing plant showed an increase in production output as the elimination of waste on equipment resulted in speedy operations.

1.8.4. Overall equipment effectiveness

Kaizen Events were found to have a significant relationship with overall equipment effectiveness. The result is consistent with findings from the literature. Mano et al. (2014) also found a strong link between kaizen practices and improved performance in the agriculture sector. In addition, Berhe (2021) conducted a study in Ethiopia, where the results showed that kaizen techniques resulted in increased production and productivity due to increased overall equipment effectiveness. Besides that, JICA and UNICO International Corporation (2009) conducted a study in Bangladesh, where the results showed that kaizen implementation reduced machine stoppages by 45.7%. However, Kaizen 5S and total quality management showed no significant relationship to overall equipment effectiveness.

Kaizen Events and 5s showed no significant relationship to productivity, quality, speed, and overall equipment effectiveness. Furthermore, Kaizen events showed no significant relationship to speed, and in addition, total quality management showed no significant relationship between quality and speed. These results mentioned are not consistent with the findings from the literature reviewed. This could be because of employees’ attitude as the most serious challenge the companies were facing, followed by financial constraints, insufficient participation by workers, ineffective training, misconceptions about Kaizen, ineffective Kaizen performance measures, organisation structure, and ineffective communication systems. The least was a lack of management support or leadership and other unspecified areas, as shown in Table 1. The challenges found were consistent with findings by other researchers (Chiarini et al., 2018; Chung, 2018; Fiorillo et al., 2021).

1.9. Conclusion

In view of the findings of the research, there is a need for more manufacturing companies to adopt and implement the Kaizen practices with a view to improving the operations performance, as evidenced by those that adopted and implemented the concept. The Kaizen Institute of Zambia (KIZ) needs to do more sensitisation on the least implemented common practices to have a holistic approach to continuous improvement and should intensify registration, monitoring, and evaluation of concept implementation and progress reports to be shared with relevant stakeholders in a timely fashion. The government of the Republic of Zambia (GRZ) should consider implementing promotional activities on the Kaizen philosophy in all economic sectors, whether private or public, and involve all concerned partners such as ZAM, ZDA, and line Ministries. There is a need to institutionalise the Kaizen concept in all sectors.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors received no direct funding for this research.

Notes on contributors

Chanda Sichinsambwe

Chanda Sichinsambwe is a senior lecturer with over 25 years at the Copperbelt University, School of Business. His research interests include TQM, Quality Management, Lean Manufacturing, Operations Management, Process Improvement, Production Planning, and Inventory Management Optimization

Peter Lubosi Simasiku

Peter Lubosi Simasiku has over 12 years of combined industry and teaching experience. Simasiku holds an MSc in Supply Chain Management & Logistics from the University of Southampton and a BSc in Production Management from Copperbelt University. Prior to joining Copperbelt University, he worked in the Manufacturing and Brewing Industries for over 5 years in Zambia as a Team Leader, Maintenance Planner, Packing plant Superintendent, production supervisor, and packaging supervisor.

Shem Sikombe

Shem Sikombe has over 10 years of teaching, administrative and research experience at the university level. His research interest is in Sustainable Procurement, Supply Chain Management, and SME-oriented Public Procurement policies. Sikombe has an earned PhD in Supply Chain Management from Kwazulu-Natal in South Africa.

Harris Nyimbili

Harris Nyimbili has over 20 years of experience in Supply and Distribution, sourcing and procurement. His main role is to ensure the effective development of procedures and processes and monitor that they are working to ensure the safety and efficiency of the entire Supply Chain. Nyimbili holds a BSc in Production Management and an MBA, he is currently a Lecturer at the Copperbelt University, School of Business.